Many types of devices for detachably locking two telescopically movable elements in relation to each other are known, such as simple screw joints, cotter and hole joints, wedge joints, conical ring joints, eccentric joints, etc. These devices exhibit different properties and drawbacks.
Cotter and hole joints and other shape-dependent joints (e. g. SE 870387-6) provide a secure connection but only allow stepwise adjustment of the elements in relation to each other. Other joints such as screw joints, are dependent on friction and thus allow stepless setting, but they often require such high contact forces to ensure reliable locking that the contact surfaces become deformed.
SE 8203018-0 describes a device with an intermediate element 8 to spread the contact force over a larger area with the object of avoiding damage to the contact surfaces. A drawback with this device, however, is that the locking force is so great that a screw must be used, which is an inconvenience.
EP 0209756 describes a device in which a rubber ring 4 having circular cross section is used as a locking and sealing element. A drawback with this device, however, is that setting the two elements in relation to each other is complicated since the joint must be opened and the rubber ring rolled to the desired position.
DE 3143793 describes a device in which a plastic washer 40 with a conical end piece is clamped between corresponding conical surfaces on the outer and inner telescopic elements. A drawback with this, however, is that the fit between the inner telescopic element and the washer must be so accurate that it is rather difficult to move it along the inner telescopic element. Another drawback is that the washer is thus subject to wear.
Common to these known solutions is that they are generally operated by movement of the operator's hand and that the operation cannot be performed at a distance from the locking unit. In the use of telescopically adjustable handles for implements, such as cleaning handles, particularly cleaning handles for floor care such as floor mops it is, for ergonomic reasons, extremely necessary to be able to operate the telescopic function from the upper part of the handle, without the need for any turning movement. From the ergonomic aspect it is most advantageous if control can be performed by means of pressure close to the upper part of the handle, at right angles to the longitudinal axis of the handle, and for the application of this pressure via a compressive movement of the operator's hand to give rise to release of the locking device.